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25
Operation
Two-clamp stake-less measurement
Before making a stake-less measurement, please follow the procedures contained in the “Ground resistance
measurement” on page 22.
Electrode
under test
I
CAT IV
300V
12-15V
1.2A
H
E
S
V
1. Ensure the left hand rotary selector switch is in the
OFF
position.
2. Connect the instrument as shown above.
3. Close the Megger Current Clamp around the conductor under test. Ensure the arrow on the side of the jaw is
pointing in the same direction as the arrow on the Megger Voltage Clamp.
4. Close the Megger Voltage Clamp around the conductor under test. Ensure the arrow on the side of the jaw is
pointing in the same direction as the arrow on the Megger Current Clamp.
(If one of the clamps is reversed, the main display shows ‘Err’ momentarily with ‘REV’ on the auxiliary display
together with the V clamp symbols).
5. Ensure a minimum separation of 100 mm between the Megger Current Clamp and Megger Voltage Clamp.
6. Set the left hand rotary selctor switch to
RE
.
7. Set the right hand rotary selector switch to the
position.
8. Press and release the
TEST
button. The instrument will perform pre-measurement checks, the status of
which will be indicated on the display.
9. The stake-less resistance reading will be displayed.
Caution: Ensure that the Megger Voltage Clamp and Megger Current Clamp jaw mating
surfaces are free of dust and contamination, they must contact completely when the Megger
Voltage Clamp and Megger Current Clamp are closed.
Note:
Currents carried by conductors in close proximity to the Megger Voltage Clamp and Megger Current
Clamp may affect calibration and reduce the accuracy of measurements made.
Note:
If the Megger Voltage Clamp opens at after the
TEST
button is pressed, the test will be aborted.
